//=============================================================================
//
//                               OpenMesh
//      Copyright (C) 2001-2005 by Computer Graphics Group, RWTH Aachen
//                           www.openmesh.org
//
//-----------------------------------------------------------------------------
//
//                                License
//
//   This library is free software; you can redistribute it and/or modify it
//   under the terms of the GNU Library General Public License as published
//   by the Free Software Foundation, version 2.
//
//   This library is distributed in the hope that it will be useful, but
//   WITHOUT ANY WARRANTY; without even the implied warranty of
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//   Library General Public License for more details.
//
//   You should have received a copy of the GNU Library General Public
//   License along with this library; if not, write to the Free Software
//   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
//-----------------------------------------------------------------------------
//
//   $Revision: 1.4 $
//   $Date: 2005-12-21 13:55:21 $
//
//=============================================================================


//=============================================================================
//
//  CLASS ModQuadricT
//
//=============================================================================

#ifndef OSG_MODQUADRIC_HH
#define OSG_MODQUADRIC_HH


//== INCLUDES =================================================================

#include <float.h>
#include <Tools/Decimater/ModBaseT.hh>
#include <Core/Utils/Property.hh>
#include <Core/Utils/vector_cast.hh>
#include <Tools/Geometry/QuadricT.hh>


//== NAMESPACE ================================================================

namespace OpenMesh  {
	namespace Decimater {


		//== CLASS DEFINITION =========================================================


		/** Mesh decimation module computing collapse priority based on error quadrics.
		*
		*  This module can be used as a binary and non-binary module.
		*/
		template <class DecimaterType>
		class ModQuadricT : public ModBaseT<DecimaterType>
		{
		public:

			// Defines the types Self, Handle, Base, Mesh, and CollapseInfo
			// and the memberfunction name()
			DECIMATING_MODULE( ModQuadricT, DecimaterType, Quadric );

		public:

			/** Constructor
			*  \internal
			*/
			ModQuadricT( DecimaterType &_dec )
				: Base(_dec, false), mesh_(Self::mesh())
			{
				unset_max_err();
				mesh_.add_property( quadrics_ );
			}


			/// Destructor
			virtual ~ModQuadricT()
			{
				mesh_.remove_property(quadrics_);
			}


		public: // inherited

			/// Initalize the module and prepare the mesh for decimation.
			virtual void initialize(void);

			/** Compute collapse priority based on error quadrics.
			*
			*  \see ModBaseT::collapse_priority() for return values
			*  \see set_max_err()
			*/
			virtual float collapse_priority(const CollapseInfo& _ci)
			{
				using namespace OpenMesh;

				typedef Geometry::QuadricT<double> Q;

				Q q = mesh_.property(quadrics_, _ci.v0);
				q += mesh_.property(quadrics_, _ci.v1);

				double err = q(_ci.p1);

				//min_ = std::min(err, min_);
				//max_ = std::max(err, max_);

				//double err = q( p );

				return float( (err < max_err_) ? err : Self::ILLEGAL_COLLAPSE );
			}


			/// Post-process halfedge collapse (accumulate quadrics)
			virtual void postprocess_collapse(const CollapseInfo& _ci)
			{
				mesh_.property(quadrics_, _ci.v1) +=
					mesh_.property(quadrics_, _ci.v0);
			}



		public: // specific methods

			/** Set maximum quadric error constraint and enable binary mode.
			*  \param _err    Maximum error allowed
			*  \param _binary Let the module work in non-binary mode in spite of the
			*                 enabled constraint.
			*  \see unset_max_err()
			*/
			void set_max_err(double _err, bool _binary=true)
			{
				max_err_ = _err;
				Self::set_binary(_binary);
			}

			/// Unset maximum quadric error constraint and restore non-binary mode.
			/// \see set_max_err()
			void unset_max_err(void)
			{
				max_err_ = DBL_MAX;
				Self::set_binary(false);
			}

			/// Return value of max. allowed error.
			double max_err() const { return max_err_; }


		private:

			Mesh& mesh_;

			// maximum quadric error
			double max_err_;

			// this vertex property stores a quadric for each vertex
			VPropHandleT< Geometry::QuadricT<double> >  quadrics_;
		};

		//=============================================================================
	} // END_NS_DECIMATER
} // END_NS_OPENMESH
//=============================================================================
#if defined(OM_INCLUDE_TEMPLATES) && !defined(OPENMESH_DECIMATER_MODQUADRIC_CC)
#define OSG_MODQUADRIC_TEMPLATES
#include "ModQuadricT.cc"
#endif
//=============================================================================
#endif // OSG_MODQUADRIC_HH defined
//=============================================================================

